1 @c Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
2 @c Free Software Foundation, Inc.
3 @c This is part of the GCC manual.
4 @c For copying conditions, see the file gcc.texi.
7 @chapter Source Tree Structure and Build System
9 This chapter describes the structure of the GCC source tree, and how
10 GCC is built. The user documentation for building and installing GCC
11 is in a separate manual (@uref{http://gcc.gnu.org/install/}), with
12 which it is presumed that you are familiar.
15 * Configure Terms:: Configuration terminology and history.
16 * Top Level:: The top level source directory.
17 * gcc Directory:: The @file{gcc} subdirectory.
20 @include configterms.texi
23 @section Top Level Source Directory
25 The top level source directory in a GCC distribution contains several
26 files and directories that are shared with other software
27 distributions such as that of GNU Binutils. It also contains several
28 subdirectories that contain parts of GCC and its runtime libraries:
32 The Boehm conservative garbage collector, used as part of the Java
36 Autoconf macros and Makefile fragments used throughout the tree.
39 Contributed scripts that may be found useful in conjunction with GCC@.
40 One of these, @file{contrib/texi2pod.pl}, is used to generate man
41 pages from Texinfo manuals as part of the GCC build process.
44 The support for fixing system headers to work with GCC@. See
45 @file{fixincludes/README} for more information. The headers fixed by
46 this mechanism are installed in @file{@var{libsubdir}/include-fixed}.
47 Along with those headers, @file{README-fixinc} is also installed, as
48 @file{@var{libsubdir}/include-fixed/README}.
51 The main sources of GCC itself (except for runtime libraries),
52 including optimizers, support for different target architectures,
53 language front ends, and testsuites. @xref{gcc Directory, , The
54 @file{gcc} Subdirectory}, for details.
57 Support tools for GNAT.
60 Headers for the @code{libiberty} library.
63 GNU @code{libintl}, from GNU @code{gettext}, for systems which do not
64 include it in @code{libc}.
67 The Ada runtime library.
70 The C preprocessor library.
73 The Decimal Float support library.
76 The @code{libffi} library, used as part of the Java runtime library.
79 The GCC runtime library.
82 The Fortran runtime library.
85 The Go runtime library. The bulk of this library is mirrored from the
86 @uref{http://code.google.com/@/p/@/go/, master Go repository}.
89 The GNU OpenMP runtime library.
92 The @code{libiberty} library, used for portability and for some
93 generally useful data structures and algorithms. @xref{Top, ,
94 Introduction, libiberty, @sc{gnu} libiberty}, for more information
98 The Java runtime library.
101 The @code{libmudflap} library, used for instrumenting pointer and array
102 dereferencing operations.
105 The Objective-C and Objective-C++ runtime library.
108 The Stack protector runtime library.
111 The C++ runtime library.
114 Plugin used by @command{gold} if link-time optimizations are enabled.
116 @item maintainer-scripts
117 Scripts used by the @code{gccadmin} account on @code{gcc.gnu.org}.
120 The @code{zlib} compression library, used by the Java front end, as
121 part of the Java runtime library, and for compressing and uncompressing
122 GCC's intermediate language in LTO object files.
125 The build system in the top level directory, including how recursion
126 into subdirectories works and how building runtime libraries for
127 multilibs is handled, is documented in a separate manual, included
128 with GNU Binutils. @xref{Top, , GNU configure and build system,
129 configure, The GNU configure and build system}, for details.
132 @section The @file{gcc} Subdirectory
134 The @file{gcc} directory contains many files that are part of the C
135 sources of GCC, other files used as part of the configuration and
136 build process, and subdirectories including documentation and a
137 testsuite. The files that are sources of GCC are documented in a
138 separate chapter. @xref{Passes, , Passes and Files of the Compiler}.
141 * Subdirectories:: Subdirectories of @file{gcc}.
142 * Configuration:: The configuration process, and the files it uses.
143 * Build:: The build system in the @file{gcc} directory.
144 * Makefile:: Targets in @file{gcc/Makefile}.
145 * Library Files:: Library source files and headers under @file{gcc/}.
146 * Headers:: Headers installed by GCC.
147 * Documentation:: Building documentation in GCC.
148 * Front End:: Anatomy of a language front end.
149 * Back End:: Anatomy of a target back end.
153 @subsection Subdirectories of @file{gcc}
155 The @file{gcc} directory contains the following subdirectories:
159 Subdirectories for various languages. Directories containing a file
160 @file{config-lang.in} are language subdirectories. The contents of
161 the subdirectories @file{cp} (for C++), @file{lto} (for LTO),
162 @file{objc} (for Objective-C) and @file{objcp} (for Objective-C++) are
163 documented in this manual (@pxref{Passes, , Passes and Files of the
164 Compiler}); those for other languages are not. @xref{Front End, ,
165 Anatomy of a Language Front End}, for details of the files in these
169 Configuration files for supported architectures and operating
170 systems. @xref{Back End, , Anatomy of a Target Back End}, for
171 details of the files in this directory.
174 Texinfo documentation for GCC, together with automatically generated
175 man pages and support for converting the installation manual to
176 HTML@. @xref{Documentation}.
179 System headers installed by GCC, mainly those required by the C
180 standard of freestanding implementations. @xref{Headers, , Headers
181 Installed by GCC}, for details of when these and other headers are
185 Message catalogs with translations of messages produced by GCC into
186 various languages, @file{@var{language}.po}. This directory also
187 contains @file{gcc.pot}, the template for these message catalogues,
188 @file{exgettext}, a wrapper around @command{gettext} to extract the
189 messages from the GCC sources and create @file{gcc.pot}, which is run
190 by @samp{make gcc.pot}, and @file{EXCLUDES}, a list of files from
191 which messages should not be extracted.
194 The GCC testsuites (except for those for runtime libraries).
199 @subsection Configuration in the @file{gcc} Directory
201 The @file{gcc} directory is configured with an Autoconf-generated
202 script @file{configure}. The @file{configure} script is generated
203 from @file{configure.ac} and @file{aclocal.m4}. From the files
204 @file{configure.ac} and @file{acconfig.h}, Autoheader generates the
205 file @file{config.in}. The file @file{cstamp-h.in} is used as a
209 * Config Fragments:: Scripts used by @file{configure}.
210 * System Config:: The @file{config.build}, @file{config.host}, and
211 @file{config.gcc} files.
212 * Configuration Files:: Files created by running @file{configure}.
215 @node Config Fragments
216 @subsubsection Scripts Used by @file{configure}
218 @file{configure} uses some other scripts to help in its work:
221 @item The standard GNU @file{config.sub} and @file{config.guess}
222 files, kept in the top level directory, are used.
224 @item The file @file{config.gcc} is used to handle configuration
225 specific to the particular target machine. The file
226 @file{config.build} is used to handle configuration specific to the
227 particular build machine. The file @file{config.host} is used to handle
228 configuration specific to the particular host machine. (In general,
229 these should only be used for features that cannot reasonably be tested in
230 Autoconf feature tests.)
231 @xref{System Config, , The @file{config.build}; @file{config.host};
232 and @file{config.gcc} Files}, for details of the contents of these files.
234 @item Each language subdirectory has a file
235 @file{@var{language}/config-lang.in} that is used for
236 front-end-specific configuration. @xref{Front End Config, , The Front
237 End @file{config-lang.in} File}, for details of this file.
239 @item A helper script @file{configure.frag} is used as part of
240 creating the output of @file{configure}.
244 @subsubsection The @file{config.build}; @file{config.host}; and @file{config.gcc} Files
246 The @file{config.build} file contains specific rules for particular systems
247 which GCC is built on. This should be used as rarely as possible, as the
248 behavior of the build system can always be detected by autoconf.
250 The @file{config.host} file contains specific rules for particular systems
251 which GCC will run on. This is rarely needed.
253 The @file{config.gcc} file contains specific rules for particular systems
254 which GCC will generate code for. This is usually needed.
256 Each file has a list of the shell variables it sets, with descriptions, at the
259 FIXME: document the contents of these files, and what variables should
260 be set to control build, host and target configuration.
262 @include configfiles.texi
265 @subsection Build System in the @file{gcc} Directory
267 FIXME: describe the build system, including what is built in what
268 stages. Also list the various source files that are used in the build
269 process but aren't source files of GCC itself and so aren't documented
270 below (@pxref{Passes}).
272 @include makefile.texi
275 @subsection Library Source Files and Headers under the @file{gcc} Directory
277 FIXME: list here, with explanation, all the C source files and headers
278 under the @file{gcc} directory that aren't built into the GCC
279 executable but rather are part of runtime libraries and object files,
280 such as @file{crtstuff.c} and @file{unwind-dw2.c}. @xref{Headers, ,
281 Headers Installed by GCC}, for more information about the
282 @file{ginclude} directory.
285 @subsection Headers Installed by GCC
287 In general, GCC expects the system C library to provide most of the
288 headers to be used with it. However, GCC will fix those headers if
289 necessary to make them work with GCC, and will install some headers
290 required of freestanding implementations. These headers are installed
291 in @file{@var{libsubdir}/include}. Headers for non-C runtime
292 libraries are also installed by GCC; these are not documented here.
293 (FIXME: document them somewhere.)
295 Several of the headers GCC installs are in the @file{ginclude}
296 directory. These headers, @file{iso646.h},
297 @file{stdarg.h}, @file{stdbool.h}, and @file{stddef.h},
298 are installed in @file{@var{libsubdir}/include},
299 unless the target Makefile fragment (@pxref{Target Fragment})
300 overrides this by setting @code{USER_H}.
302 In addition to these headers and those generated by fixing system
303 headers to work with GCC, some other headers may also be installed in
304 @file{@var{libsubdir}/include}. @file{config.gcc} may set
305 @code{extra_headers}; this specifies additional headers under
306 @file{config} to be installed on some systems.
308 GCC installs its own version of @code{<float.h>}, from @file{ginclude/float.h}.
309 This is done to cope with command-line options that change the
310 representation of floating point numbers.
312 GCC also installs its own version of @code{<limits.h>}; this is generated
313 from @file{glimits.h}, together with @file{limitx.h} and
314 @file{limity.h} if the system also has its own version of
315 @code{<limits.h>}. (GCC provides its own header because it is
316 required of ISO C freestanding implementations, but needs to include
317 the system header from its own header as well because other standards
318 such as POSIX specify additional values to be defined in
319 @code{<limits.h>}.) The system's @code{<limits.h>} header is used via
320 @file{@var{libsubdir}/include/syslimits.h}, which is copied from
321 @file{gsyslimits.h} if it does not need fixing to work with GCC; if it
322 needs fixing, @file{syslimits.h} is the fixed copy.
324 GCC can also install @code{<tgmath.h>}. It will do this when
325 @file{config.gcc} sets @code{use_gcc_tgmath} to @code{yes}.
328 @subsection Building Documentation
330 The main GCC documentation is in the form of manuals in Texinfo
331 format. These are installed in Info format; DVI versions may be
332 generated by @samp{make dvi}, PDF versions by @samp{make pdf}, and
333 HTML versions by @samp{make html}. In addition, some man pages are
334 generated from the Texinfo manuals, there are some other text files
335 with miscellaneous documentation, and runtime libraries have their own
336 documentation outside the @file{gcc} directory. FIXME: document the
337 documentation for runtime libraries somewhere.
340 * Texinfo Manuals:: GCC manuals in Texinfo format.
341 * Man Page Generation:: Generating man pages from Texinfo manuals.
342 * Miscellaneous Docs:: Miscellaneous text files with documentation.
345 @node Texinfo Manuals
346 @subsubsection Texinfo Manuals
348 The manuals for GCC as a whole, and the C and C++ front ends, are in
349 files @file{doc/*.texi}. Other front ends have their own manuals in
350 files @file{@var{language}/*.texi}. Common files
351 @file{doc/include/*.texi} are provided which may be included in
352 multiple manuals; the following files are in @file{doc/include}:
356 The GNU Free Documentation License.
358 The section ``Funding Free Software''.
359 @item gcc-common.texi
360 Common definitions for manuals.
363 The GNU General Public License.
365 A copy of @file{texinfo.tex} known to work with the GCC manuals.
368 DVI-formatted manuals are generated by @samp{make dvi}, which uses
369 @command{texi2dvi} (via the Makefile macro @code{$(TEXI2DVI)}).
370 PDF-formatted manuals are generated by @samp{make pdf}, which uses
371 @command{texi2pdf} (via the Makefile macro @code{$(TEXI2PDF)}). HTML
372 formatted manuals are generated by @samp{make html}. Info
373 manuals are generated by @samp{make info} (which is run as part of
374 a bootstrap); this generates the manuals in the source directory,
375 using @command{makeinfo} via the Makefile macro @code{$(MAKEINFO)},
376 and they are included in release distributions.
378 Manuals are also provided on the GCC web site, in both HTML and
379 PostScript forms. This is done via the script
380 @file{maintainer-scripts/update_web_docs_svn}. Each manual to be
381 provided online must be listed in the definition of @code{MANUALS} in
382 that file; a file @file{@var{name}.texi} must only appear once in the
383 source tree, and the output manual must have the same name as the
384 source file. (However, other Texinfo files, included in manuals but
385 not themselves the root files of manuals, may have names that appear
386 more than once in the source tree.) The manual file
387 @file{@var{name}.texi} should only include other files in its own
388 directory or in @file{doc/include}. HTML manuals will be generated by
389 @samp{makeinfo --html}, PostScript manuals by @command{texi2dvi}
390 and @command{dvips}, and PDF manuals by @command{texi2pdf}.
391 All Texinfo files that are parts of manuals must
392 be version-controlled, even if they are generated files, for the
393 generation of online manuals to work.
395 The installation manual, @file{doc/install.texi}, is also provided on
396 the GCC web site. The HTML version is generated by the script
397 @file{doc/install.texi2html}.
399 @node Man Page Generation
400 @subsubsection Man Page Generation
402 Because of user demand, in addition to full Texinfo manuals, man pages
403 are provided which contain extracts from those manuals. These man
404 pages are generated from the Texinfo manuals using
405 @file{contrib/texi2pod.pl} and @command{pod2man}. (The man page for
406 @command{g++}, @file{cp/g++.1}, just contains a @samp{.so} reference
407 to @file{gcc.1}, but all the other man pages are generated from
410 Because many systems may not have the necessary tools installed to
411 generate the man pages, they are only generated if the
412 @file{configure} script detects that recent enough tools are
413 installed, and the Makefiles allow generating man pages to fail
414 without aborting the build. Man pages are also included in release
415 distributions. They are generated in the source directory.
417 Magic comments in Texinfo files starting @samp{@@c man} control what
418 parts of a Texinfo file go into a man page. Only a subset of Texinfo
419 is supported by @file{texi2pod.pl}, and it may be necessary to add
420 support for more Texinfo features to this script when generating new
421 man pages. To improve the man page output, some special Texinfo
422 macros are provided in @file{doc/include/gcc-common.texi} which
423 @file{texi2pod.pl} understands:
427 Use in the form @samp{@@table @@gcctabopt} for tables of options,
428 where for printed output the effect of @samp{@@code} is better than
429 that of @samp{@@option} but for man page output a different effect is
432 Use for summary lists of options in manuals.
434 Use at the end of each line inside @samp{@@gccoptlist}. This is
435 necessary to avoid problems with differences in how the
436 @samp{@@gccoptlist} macro is handled by different Texinfo formatters.
439 FIXME: describe the @file{texi2pod.pl} input language and magic
440 comments in more detail.
442 @node Miscellaneous Docs
443 @subsubsection Miscellaneous Documentation
445 In addition to the formal documentation that is installed by GCC,
446 there are several other text files in the @file{gcc} subdirectory
447 with miscellaneous documentation:
451 Notes on GCC's Native Language Support. FIXME: this should be part of
452 this manual rather than a separate file.
454 Notes on the Free Translation Project.
457 The GNU General Public License, Versions 2 and 3.
460 The GNU Lesser General Public License, Versions 2.1 and 3.
463 Change log files for various parts of GCC@.
465 Details of a few changes to the GCC front-end interface. FIXME: the
466 information in this file should be part of general documentation of
467 the front-end interface in this manual.
469 Information about new features in old versions of GCC@. (For recent
470 versions, the information is on the GCC web site.)
471 @item README.Portability
472 Information about portability issues when writing code in GCC@. FIXME:
473 why isn't this part of this manual or of the GCC Coding Conventions?
476 FIXME: document such files in subdirectories, at least @file{config},
477 @file{cp}, @file{objc}, @file{testsuite}.
480 @subsection Anatomy of a Language Front End
482 A front end for a language in GCC has the following parts:
486 A directory @file{@var{language}} under @file{gcc} containing source
487 files for that front end. @xref{Front End Directory, , The Front End
488 @file{@var{language}} Directory}, for details.
490 A mention of the language in the list of supported languages in
491 @file{gcc/doc/install.texi}.
493 A mention of the name under which the language's runtime library is
494 recognized by @option{--enable-shared=@var{package}} in the
495 documentation of that option in @file{gcc/doc/install.texi}.
497 A mention of any special prerequisites for building the front end in
498 the documentation of prerequisites in @file{gcc/doc/install.texi}.
500 Details of contributors to that front end in
501 @file{gcc/doc/contrib.texi}. If the details are in that front end's
502 own manual then there should be a link to that manual's list in
505 Information about support for that language in
506 @file{gcc/doc/frontends.texi}.
508 Information about standards for that language, and the front end's
509 support for them, in @file{gcc/doc/standards.texi}. This may be a
510 link to such information in the front end's own manual.
512 Details of source file suffixes for that language and @option{-x
513 @var{lang}} options supported, in @file{gcc/doc/invoke.texi}.
515 Entries in @code{default_compilers} in @file{gcc.c} for source file
516 suffixes for that language.
518 Preferably testsuites, which may be under @file{gcc/testsuite} or
519 runtime library directories. FIXME: document somewhere how to write
522 Probably a runtime library for the language, outside the @file{gcc}
523 directory. FIXME: document this further.
525 Details of the directories of any runtime libraries in
526 @file{gcc/doc/sourcebuild.texi}.
528 Check targets in @file{Makefile.def} for the top-level @file{Makefile}
529 to check just the compiler or the compiler and runtime library for the
533 If the front end is added to the official GCC source repository, the
534 following are also necessary:
538 At least one Bugzilla component for bugs in that front end and runtime
539 libraries. This category needs to be added to the Bugzilla database.
541 Normally, one or more maintainers of that front end listed in
544 Mentions on the GCC web site in @file{index.html} and
545 @file{frontends.html}, with any relevant links on
546 @file{readings.html}. (Front ends that are not an official part of
547 GCC may also be listed on @file{frontends.html}, with relevant links.)
549 A news item on @file{index.html}, and possibly an announcement on the
550 @email{gcc-announce@@gcc.gnu.org} mailing list.
552 The front end's manuals should be mentioned in
553 @file{maintainer-scripts/update_web_docs_svn} (@pxref{Texinfo Manuals})
554 and the online manuals should be linked to from
555 @file{onlinedocs/index.html}.
557 Any old releases or CVS repositories of the front end, before its
558 inclusion in GCC, should be made available on the GCC FTP site
559 @uref{ftp://gcc.gnu.org/pub/gcc/old-releases/}.
561 The release and snapshot script @file{maintainer-scripts/gcc_release}
562 should be updated to generate appropriate tarballs for this front end.
564 If this front end includes its own version files that include the
565 current date, @file{maintainer-scripts/update_version} should be
570 * Front End Directory:: The front end @file{@var{language}} directory.
571 * Front End Config:: The front end @file{config-lang.in} file.
572 * Front End Makefile:: The front end @file{Make-lang.in} file.
575 @node Front End Directory
576 @subsubsection The Front End @file{@var{language}} Directory
578 A front end @file{@var{language}} directory contains the source files
579 of that front end (but not of any runtime libraries, which should be
580 outside the @file{gcc} directory). This includes documentation, and
581 possibly some subsidiary programs built alongside the front end.
582 Certain files are special and other parts of the compiler depend on
587 This file is required in all language subdirectories. @xref{Front End
588 Config, , The Front End @file{config-lang.in} File}, for details of
591 This file is required in all language subdirectories. @xref{Front End
592 Makefile, , The Front End @file{Make-lang.in} File}, for details of its
595 This file registers the set of switches that the front end accepts on
596 the command line, and their @option{--help} text. @xref{Options}.
598 This file provides entries for @code{default_compilers} in
599 @file{gcc.c} which override the default of giving an error that a
600 compiler for that language is not installed.
601 @item @var{language}-tree.def
602 This file, which need not exist, defines any language-specific tree
606 @node Front End Config
607 @subsubsection The Front End @file{config-lang.in} File
609 Each language subdirectory contains a @file{config-lang.in} file. In
610 addition the main directory contains @file{c-config-lang.in}, which
611 contains limited information for the C language. This file is a shell
612 script that may define some variables describing the language:
616 This definition must be present, and gives the name of the language
617 for some purposes such as arguments to @option{--enable-languages}.
619 If defined, this variable lists (space-separated) language front ends
620 other than C that this front end requires to be enabled (with the
621 names given being their @code{language} settings). For example, the
622 Java front end depends on the C++ front end, so sets
623 @samp{lang_requires=c++}.
624 @item subdir_requires
625 If defined, this variable lists (space-separated) front end directories
626 other than C that this front end requires to be present. For example,
627 the Objective-C++ front end uses source files from the C++ and
628 Objective-C front ends, so sets @samp{subdir_requires="cp objc"}.
630 If defined, this variable lists (space-separated) targets in the top
631 level @file{Makefile} to build the runtime libraries for this
632 language, such as @code{target-libobjc}.
634 If defined, this variable lists (space-separated) top level
635 directories (parallel to @file{gcc}), apart from the runtime libraries,
636 that should not be configured if this front end is not built.
637 @item build_by_default
638 If defined to @samp{no}, this language front end is not built unless
639 enabled in a @option{--enable-languages} argument. Otherwise, front
640 ends are built by default, subject to any special logic in
641 @file{configure.ac} (as is present to disable the Ada front end if the
642 Ada compiler is not already installed).
644 If defined to @samp{yes}, this front end is built in stage1 of the
645 bootstrap. This is only relevant to front ends written in their own
648 If defined, a space-separated list of compiler executables that will
649 be run by the driver. The names here will each end
650 with @samp{\$(exeext)}.
652 If defined, a space-separated list of files that should be generated
653 by @file{configure} substituting values in them. This mechanism can
654 be used to create a file @file{@var{language}/Makefile} from
655 @file{@var{language}/Makefile.in}, but this is deprecated, building
656 everything from the single @file{gcc/Makefile} is preferred.
658 If defined, a space-separated list of files that should be scanned by
659 @file{gengtype.c} to generate the garbage collection tables and routines for
660 this language. This excludes the files that are common to all front
661 ends. @xref{Type Information}.
665 @node Front End Makefile
666 @subsubsection The Front End @file{Make-lang.in} File
668 Each language subdirectory contains a @file{Make-lang.in} file. It contains
669 targets @code{@var{lang}.@var{hook}} (where @code{@var{lang}} is the
670 setting of @code{language} in @file{config-lang.in}) for the following
671 values of @code{@var{hook}}, and any other Makefile rules required to
672 build those targets (which may if necessary use other Makefiles
673 specified in @code{outputs} in @file{config-lang.in}, although this is
674 deprecated). It also adds any testsuite targets that can use the
675 standard rule in @file{gcc/Makefile.in} to the variable
682 FIXME: exactly what goes in each of these targets?
684 Build an @command{etags} @file{TAGS} file in the language subdirectory
687 Build info documentation for the front end, in the build directory.
688 This target is only called by @samp{make bootstrap} if a suitable
689 version of @command{makeinfo} is available, so does not need to check
690 for this, and should fail if an error occurs.
692 Build DVI documentation for the front end, in the build directory.
693 This should be done using @code{$(TEXI2DVI)}, with appropriate
694 @option{-I} arguments pointing to directories of included files.
696 Build PDF documentation for the front end, in the build directory.
697 This should be done using @code{$(TEXI2PDF)}, with appropriate
698 @option{-I} arguments pointing to directories of included files.
700 Build HTML documentation for the front end, in the build directory.
702 Build generated man pages for the front end from Texinfo manuals
703 (@pxref{Man Page Generation}), in the build directory. This target
704 is only called if the necessary tools are available, but should ignore
705 errors so as not to stop the build if errors occur; man pages are
706 optional and the tools involved may be installed in a broken way.
708 Install everything that is part of the front end, apart from the
709 compiler executables listed in @code{compilers} in
710 @file{config-lang.in}.
712 Install info documentation for the front end, if it is present in the
713 source directory. This target should have dependencies on info files
714 that should be installed.
716 Install man pages for the front end. This target should ignore
719 Install headers needed for plugins.
721 Copies its dependencies into the source directory. This generally should
722 be used for generated files such as Bison output files which are not
723 version-controlled, but should be included in any release tarballs. This
724 target will be executed during a bootstrap if
725 @samp{--enable-generated-files-in-srcdir} was specified as a
726 @file{configure} option.
729 Copies its dependencies into the source directory. These targets will be
730 executed during a bootstrap if @samp{--enable-generated-files-in-srcdir}
731 was specified as a @file{configure} option.
733 Uninstall files installed by installing the compiler. This is
734 currently documented not to be supported, so the hook need not do
739 @itemx maintainer-clean
740 The language parts of the standard GNU
741 @samp{*clean} targets. @xref{Standard Targets, , Standard Targets for
742 Users, standards, GNU Coding Standards}, for details of the standard
743 targets. For GCC, @code{maintainer-clean} should delete
744 all generated files in the source directory that are not version-controlled,
745 but should not delete anything that is.
748 @file{Make-lang.in} must also define a variable @code{@var{lang}_OBJS}
749 to a list of host object files that are used by that language.
752 @subsection Anatomy of a Target Back End
754 A back end for a target architecture in GCC has the following parts:
758 A directory @file{@var{machine}} under @file{gcc/config}, containing a
759 machine description @file{@var{machine}.md} file (@pxref{Machine Desc,
760 , Machine Descriptions}), header files @file{@var{machine}.h} and
761 @file{@var{machine}-protos.h} and a source file @file{@var{machine}.c}
762 (@pxref{Target Macros, , Target Description Macros and Functions}),
763 possibly a target Makefile fragment @file{t-@var{machine}}
764 (@pxref{Target Fragment, , The Target Makefile Fragment}), and maybe
765 some other files. The names of these files may be changed from the
766 defaults given by explicit specifications in @file{config.gcc}.
768 If necessary, a file @file{@var{machine}-modes.def} in the
769 @file{@var{machine}} directory, containing additional machine modes to
770 represent condition codes. @xref{Condition Code}, for further details.
772 An optional @file{@var{machine}.opt} file in the @file{@var{machine}}
773 directory, containing a list of target-specific options. You can also
774 add other option files using the @code{extra_options} variable in
775 @file{config.gcc}. @xref{Options}.
777 Entries in @file{config.gcc} (@pxref{System Config, , The
778 @file{config.gcc} File}) for the systems with this target
781 Documentation in @file{gcc/doc/invoke.texi} for any command-line
782 options supported by this target (@pxref{Run-time Target, , Run-time
783 Target Specification}). This means both entries in the summary table
784 of options and details of the individual options.
786 Documentation in @file{gcc/doc/extend.texi} for any target-specific
787 attributes supported (@pxref{Target Attributes, , Defining
788 target-specific uses of @code{__attribute__}}), including where the
789 same attribute is already supported on some targets, which are
790 enumerated in the manual.
792 Documentation in @file{gcc/doc/extend.texi} for any target-specific
795 Documentation in @file{gcc/doc/extend.texi} of any target-specific
796 built-in functions supported.
798 Documentation in @file{gcc/doc/extend.texi} of any target-specific
799 format checking styles supported.
801 Documentation in @file{gcc/doc/md.texi} of any target-specific
802 constraint letters (@pxref{Machine Constraints, , Constraints for
803 Particular Machines}).
805 A note in @file{gcc/doc/contrib.texi} under the person or people who
806 contributed the target support.
808 Entries in @file{gcc/doc/install.texi} for all target triplets
809 supported with this target architecture, giving details of any special
810 notes about installation for this target, or saying that there are no
811 special notes if there are none.
813 Possibly other support outside the @file{gcc} directory for runtime
814 libraries. FIXME: reference docs for this. The @code{libstdc++} porting
815 manual needs to be installed as info for this to work, or to be a
816 chapter of this manual.
819 If the back end is added to the official GCC source repository, the
820 following are also necessary:
824 An entry for the target architecture in @file{readings.html} on the
825 GCC web site, with any relevant links.
827 Details of the properties of the back end and target architecture in
828 @file{backends.html} on the GCC web site.
830 A news item about the contribution of support for that target
831 architecture, in @file{index.html} on the GCC web site.
833 Normally, one or more maintainers of that target listed in
834 @file{MAINTAINERS}. Some existing architectures may be unmaintained,
835 but it would be unusual to add support for a target that does not have
836 a maintainer when support is added.
838 Target triplets covering all @file{config.gcc} stanzas for the target,
839 in the list in @file{contrib/config-list.mk}.
845 GCC contains several testsuites to help maintain compiler quality.
846 Most of the runtime libraries and language front ends in GCC have
847 testsuites. Currently only the C language testsuites are documented
848 here; FIXME: document the others.
851 * Test Idioms:: Idioms used in testsuite code.
852 * Test Directives:: Directives used within DejaGnu tests.
853 * Ada Tests:: The Ada language testsuites.
854 * C Tests:: The C language testsuites.
855 * libgcj Tests:: The Java library testsuites.
856 * LTO Testing:: Support for testing link-time optimizations.
857 * gcov Testing:: Support for testing gcov.
858 * profopt Testing:: Support for testing profile-directed optimizations.
859 * compat Testing:: Support for testing binary compatibility.
860 * Torture Tests:: Support for torture testing using multiple options.
864 @section Idioms Used in Testsuite Code
866 In general, C testcases have a trailing @file{-@var{n}.c}, starting
867 with @file{-1.c}, in case other testcases with similar names are added
868 later. If the test is a test of some well-defined feature, it should
869 have a name referring to that feature such as
870 @file{@var{feature}-1.c}. If it does not test a well-defined feature
871 but just happens to exercise a bug somewhere in the compiler, and a
872 bug report has been filed for this bug in the GCC bug database,
873 @file{pr@var{bug-number}-1.c} is the appropriate form of name.
874 Otherwise (for miscellaneous bugs not filed in the GCC bug database),
875 and previously more generally, test cases are named after the date on
876 which they were added. This allows people to tell at a glance whether
877 a test failure is because of a recently found bug that has not yet
878 been fixed, or whether it may be a regression, but does not give any
879 other information about the bug or where discussion of it may be
880 found. Some other language testsuites follow similar conventions.
882 In the @file{gcc.dg} testsuite, it is often necessary to test that an
883 error is indeed a hard error and not just a warning---for example,
884 where it is a constraint violation in the C standard, which must
885 become an error with @option{-pedantic-errors}. The following idiom,
886 where the first line shown is line @var{line} of the file and the line
887 that generates the error, is used for this:
890 /* @{ dg-bogus "warning" "warning in place of error" @} */
891 /* @{ dg-error "@var{regexp}" "@var{message}" @{ target *-*-* @} @var{line} @} */
894 It may be necessary to check that an expression is an integer constant
895 expression and has a certain value. To check that @code{@var{E}} has
896 value @code{@var{V}}, an idiom similar to the following is used:
899 char x[((E) == (V) ? 1 : -1)];
902 In @file{gcc.dg} tests, @code{__typeof__} is sometimes used to make
903 assertions about the types of expressions. See, for example,
904 @file{gcc.dg/c99-condexpr-1.c}. The more subtle uses depend on the
905 exact rules for the types of conditional expressions in the C
906 standard; see, for example, @file{gcc.dg/c99-intconst-1.c}.
908 It is useful to be able to test that optimizations are being made
909 properly. This cannot be done in all cases, but it can be done where
910 the optimization will lead to code being optimized away (for example,
911 where flow analysis or alias analysis should show that certain code
912 cannot be called) or to functions not being called because they have
913 been expanded as built-in functions. Such tests go in
914 @file{gcc.c-torture/execute}. Where code should be optimized away, a
915 call to a nonexistent function such as @code{link_failure ()} may be
916 inserted; a definition
929 will also be needed so that linking still succeeds when the test is
930 run without optimization. When all calls to a built-in function
931 should have been optimized and no calls to the non-built-in version of
932 the function should remain, that function may be defined as
933 @code{static} to call @code{abort ()} (although redeclaring a function
934 as static may not work on all targets).
936 All testcases must be portable. Target-specific testcases must have
937 appropriate code to avoid causing failures on unsupported systems;
938 unfortunately, the mechanisms for this differ by directory.
940 FIXME: discuss non-C testsuites here.
942 @node Test Directives
943 @section Directives used within DejaGnu tests
946 * Directives:: Syntax and descriptions of test directives.
947 * Selectors:: Selecting targets to which a test applies.
948 * Effective-Target Keywords:: Keywords describing target attributes.
949 * Add Options:: Features for @code{dg-add-options}
950 * Require Support:: Variants of @code{dg-require-@var{support}}
951 * Final Actions:: Commands for use in @code{dg-final}
955 @subsection Syntax and Descriptions of test directives
957 Test directives appear within comments in a test source file and begin
958 with @code{dg-}. Some of these are defined within DejaGnu and others
959 are local to the GCC testsuite.
961 The order in which test directives appear in a test can be important:
962 directives local to GCC sometimes override information used by the
963 DejaGnu directives, which know nothing about the GCC directives, so the
964 DejaGnu directives must precede GCC directives.
966 Several test directives include selectors (@pxref{Selectors, , })
967 which are usually preceded by the keyword @code{target} or @code{xfail}.
969 @subsubsection Specify how to build the test
972 @item @{ dg-do @var{do-what-keyword} [@{ target/xfail @var{selector} @}] @}
973 @var{do-what-keyword} specifies how the test is compiled and whether
974 it is executed. It is one of:
978 Compile with @option{-E} to run only the preprocessor.
980 Compile with @option{-S} to produce an assembly code file.
982 Compile with @option{-c} to produce a relocatable object file.
984 Compile, assemble, and link to produce an executable file.
986 Produce and run an executable file, which is expected to return
990 The default is @code{compile}. That can be overridden for a set of
991 tests by redefining @code{dg-do-what-default} within the @code{.exp}
992 file for those tests.
994 If the directive includes the optional @samp{@{ target @var{selector} @}}
995 then the test is skipped unless the target system matches the
998 If @var{do-what-keyword} is @code{run} and the directive includes
999 the optional @samp{@{ xfail @var{selector} @}} and the selector is met
1000 then the test is expected to fail. The @code{xfail} clause is ignored
1001 for other values of @var{do-what-keyword}; those tests can use
1002 directive @code{dg-xfail-if}.
1005 @subsubsection Specify additional compiler options
1008 @item @{ dg-options @var{options} [@{ target @var{selector} @}] @}
1009 This DejaGnu directive provides a list of compiler options, to be used
1010 if the target system matches @var{selector}, that replace the default
1011 options used for this set of tests.
1013 @item @{ dg-add-options @var{feature} @dots{} @}
1014 Add any compiler options that are needed to access certain features.
1015 This directive does nothing on targets that enable the features by
1016 default, or that don't provide them at all. It must come after
1017 all @code{dg-options} directives.
1018 For supported values of @var{feature} see @ref{Add Options, ,}.
1021 @subsubsection Modify the test timeout value
1023 The normal timeout limit, in seconds, is found by searching the
1027 @item the value defined by an earlier @code{dg-timeout} directive in
1030 @item variable @var{tool_timeout} defined by the set of tests
1032 @item @var{gcc},@var{timeout} set in the target board
1038 @item @{ dg-timeout @var{n} [@{target @var{selector} @}] @}
1039 Set the time limit for the compilation and for the execution of the test
1040 to the specified number of seconds.
1042 @item @{ dg-timeout-factor @var{x} [@{ target @var{selector} @}] @}
1043 Multiply the normal time limit for compilation and execution of the test
1044 by the specified floating-point factor.
1047 @subsubsection Skip a test for some targets
1050 @item @{ dg-skip-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1051 Arguments @var{include-opts} and @var{exclude-opts} are lists in which
1052 each element is a string of zero or more GCC options.
1053 Skip the test if all of the following conditions are met:
1055 @item the test system is included in @var{selector}
1057 @item for at least one of the option strings in @var{include-opts},
1058 every option from that string is in the set of options with which
1059 the test would be compiled; use @samp{"*"} for an @var{include-opts} list
1060 that matches any options; that is the default if @var{include-opts} is
1063 @item for each of the option strings in @var{exclude-opts}, at least one
1064 option from that string is not in the set of options with which the test
1065 would be compiled; use @samp{""} for an empty @var{exclude-opts} list;
1066 that is the default if @var{exclude-opts} is not specified
1069 For example, to skip a test if option @code{-Os} is present:
1072 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-Os" @} @{ "" @} @} */
1075 To skip a test if both options @code{-O2} and @code{-g} are present:
1078 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2 -g" @} @{ "" @} @} */
1081 To skip a test if either @code{-O2} or @code{-O3} is present:
1084 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2" "-O3" @} @{ "" @} @} */
1087 To skip a test unless option @code{-Os} is present:
1090 /* @{ dg-skip-if "" @{ *-*-* @} @{ "*" @} @{ "-Os" @} @} */
1093 To skip a test if either @code{-O2} or @code{-O3} is used with @code{-g}
1094 but not if @code{-fpic} is also present:
1097 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2 -g" "-O3 -g" @} @{ "-fpic" @} @} */
1100 @item @{ dg-require-effective-target @var{keyword} [@{ @var{selector} @}] @}
1101 Skip the test if the test target, including current multilib flags,
1102 is not covered by the effective-target keyword.
1103 If the directive includes the optional @samp{@{ @var{selector} @}}
1104 then the effective-target test is only performed if the target system
1105 matches the @var{selector}.
1106 This directive must appear after any @code{dg-do} directive in the test
1107 and before any @code{dg-additional-sources} directive.
1108 @xref{Effective-Target Keywords, , }.
1110 @item @{ dg-require-@var{support} args @}
1111 Skip the test if the target does not provide the required support.
1112 These directives must appear after any @code{dg-do} directive in the test
1113 and before any @code{dg-additional-sources} directive.
1114 They require at least one argument, which can be an empty string if the
1115 specific procedure does not examine the argument.
1116 @xref{Require Support, , }, for a complete list of these directives.
1119 @subsubsection Expect a test to fail for some targets
1122 @item @{ dg-xfail-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1123 Expect the test to fail if the conditions (which are the same as for
1124 @code{dg-skip-if}) are met. This does not affect the execute step.
1126 @item @{ dg-xfail-run-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1127 Expect the execute step of a test to fail if the conditions (which are
1128 the same as for @code{dg-skip-if}) are met.
1131 @subsubsection Expect the test executable to fail
1134 @item @{ dg-shouldfail @var{comment} [@{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]]] @}
1135 Expect the test executable to return a nonzero exit status if the
1136 conditions (which are the same as for @code{dg-skip-if}) are met.
1139 @subsubsection Verify compiler messages
1142 @item @{ dg-error @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1143 This DejaGnu directive appears on a source line that is expected to get
1144 an error message, or else specifies the source line associated with the
1145 message. If there is no message for that line or if the text of that
1146 message is not matched by @var{regexp} then the check fails and
1147 @var{comment} is included in the @code{FAIL} message. The check does
1148 not look for the string @samp{error} unless it is part of @var{regexp}.
1150 @item @{ dg-warning @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1151 This DejaGnu directive appears on a source line that is expected to get
1152 a warning message, or else specifies the source line associated with the
1153 message. If there is no message for that line or if the text of that
1154 message is not matched by @var{regexp} then the check fails and
1155 @var{comment} is included in the @code{FAIL} message. The check does
1156 not look for the string @samp{warning} unless it is part of @var{regexp}.
1158 @item @{ dg-message @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1159 The line is expected to get a message other than an error or warning.
1160 If there is no message for that line or if the text of that message is
1161 not matched by @var{regexp} then the check fails and @var{comment} is
1162 included in the @code{FAIL} message.
1164 @item @{ dg-bogus @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1165 This DejaGnu directive appears on a source line that should not get a
1166 message matching @var{regexp}, or else specifies the source line
1167 associated with the bogus message. It is usually used with @samp{xfail}
1168 to indicate that the message is a known problem for a particular set of
1171 @item @{ dg-excess-errors @var{comment} [@{ target/xfail @var{selector} @}] @}
1172 This DejaGnu directive indicates that the test is expected to fail due
1173 to compiler messages that are not handled by @samp{dg-error},
1174 @samp{dg-warning} or @samp{dg-bogus}. For this directive @samp{xfail}
1175 has the same effect as @samp{target}.
1177 @item @{ dg-prune-output @var{regexp} @}
1178 Prune messages matching @var{regexp} from the test output.
1181 @subsubsection Verify output of the test executable
1184 @item @{ dg-output @var{regexp} [@{ target/xfail @var{selector} @}] @}
1185 This DejaGnu directive compares @var{regexp} to the combined output
1186 that the test executable writes to @file{stdout} and @file{stderr}.
1189 @subsubsection Specify additional files for a test
1192 @item @{ dg-additional-files "@var{filelist}" @}
1193 Specify additional files, other than source files, that must be copied
1194 to the system where the compiler runs.
1196 @item @{ dg-additional-sources "@var{filelist}" @}
1197 Specify additional source files to appear in the compile line
1198 following the main test file.
1201 @subsubsection Add checks at the end of a test
1204 @item @{ dg-final @{ @var{local-directive} @} @}
1205 This DejaGnu directive is placed within a comment anywhere in the
1206 source file and is processed after the test has been compiled and run.
1207 Multiple @samp{dg-final} commands are processed in the order in which
1208 they appear in the source file. @xref{Final Actions, , }, for a list
1209 of directives that can be used within @code{dg-final}.
1213 @subsection Selecting targets to which a test applies
1215 Several test directives include @var{selector}s to limit the targets
1216 for which a test is run or to declare that a test is expected to fail
1217 on particular targets.
1221 @item one or more target triplets, possibly including wildcard characters
1222 @item a single effective-target keyword (@pxref{Effective-Target Keywords})
1223 @item a logical expression
1227 context, the selector specifies whether a test is skipped and reported
1228 as unsupported or is expected to fail. Use @samp{*-*-*} to match any
1231 A selector expression appears within curly braces and uses a single
1232 logical operator: one of @samp{!}, @samp{&&}, or @samp{||}. An
1233 operand is another selector expression, an effective-target keyword,
1234 a single target triplet, or a list of target triplets within quotes or
1235 curly braces. For example:
1238 @{ target @{ ! "hppa*-*-* ia64*-*-*" @} @}
1239 @{ target @{ powerpc*-*-* && lp64 @} @}
1240 @{ xfail @{ lp64 || vect_no_align @} @}
1243 @node Effective-Target Keywords
1244 @subsection Keywords describing target attributes
1246 Effective-target keywords identify sets of targets that support
1247 particular functionality. They are used to limit tests to be run only
1248 for particular targets, or to specify that particular sets of targets
1249 are expected to fail some tests.
1251 Effective-target keywords are defined in @file{lib/target-supports.exp} in
1252 the GCC testsuite, with the exception of those that are documented as
1253 being local to a particular test directory.
1255 The @samp{effective target} takes into account all of the compiler options
1256 with which the test will be compiled, including the multilib options.
1257 By convention, keywords ending in @code{_nocache} can also include options
1258 specified for the particular test in an earlier @code{dg-options} or
1259 @code{dg-add-options} directive.
1261 @subsubsection Data type sizes
1265 Target has 32-bit @code{int}, @code{long}, and pointers.
1268 Target has 32-bit @code{int}, 64-bit @code{long} and pointers.
1271 Target has 32-bit @code{int} and @code{long}, 64-bit @code{long long}
1275 Target has 64-bit @code{double}.
1278 Target has @code{double} that is 64 bits or longer.
1281 Target has @code{int} that is at 32 bits or longer.
1284 Target has @code{int} that is 16 bits or shorter.
1287 Target supports @code{double} that is longer than @code{float}.
1289 @item large_long_double
1290 Target supports @code{long double} that is longer than @code{double}.
1293 Target has pointers that are 32 bits or longer.
1296 Target supports array and structure sizes that are 32 bits or longer.
1299 Target has @code{wchar_t} that is at least 4 bytes.
1302 @subsubsection Fortran-specific attributes
1305 @item fortran_integer_16
1306 Target supports Fortran @code{integer} that is 16 bytes or longer.
1308 @item fortran_large_int
1309 Target supports Fortran @code{integer} kinds larger than @code{integer(8)}.
1311 @item fortran_large_real
1312 Target supports Fortran @code{real} kinds larger than @code{real(8)}.
1315 @subsubsection Vector-specific attributes
1318 @item vect_condition
1319 Target supports vector conditional operations.
1322 Target supports hardware vectors of @code{double}.
1325 Target supports hardware vectors of @code{float}.
1328 Target supports hardware vectors of @code{int}.
1331 Target supports hardware vectors of @code{long}.
1333 @item vect_long_long
1334 Target supports hardware vectors of @code{long long}.
1336 @item vect_aligned_arrays
1337 Target aligns arrays to vector alignment boundary.
1339 @item vect_hw_misalign
1340 Target supports a vector misalign access.
1343 Target does not support a vector alignment mechanism.
1345 @item vect_no_int_max
1346 Target does not support a vector max instruction on @code{int}.
1348 @item vect_no_int_add
1349 Target does not support a vector add instruction on @code{int}.
1351 @item vect_no_bitwise
1352 Target does not support vector bitwise instructions.
1354 @item vect_char_mult
1355 Target supports @code{vector char} multiplication.
1357 @item vect_short_mult
1358 Target supports @code{vector short} multiplication.
1361 Target supports @code{vector int} multiplication.
1363 @item vect_extract_even_odd
1364 Target supports vector even/odd element extraction.
1366 @item vect_extract_even_odd_wide
1367 Target supports vector even/odd element extraction of vectors with elements
1368 @code{SImode} or larger.
1370 @item vect_interleave
1371 Target supports vector interleaving.
1374 Target supports vector interleaving and extract even/odd.
1376 @item vect_strided_wide
1377 Target supports vector interleaving and extract even/odd for wide
1381 Target supports vector permutation.
1384 Target supports a hardware vector shift operation.
1386 @item vect_widen_sum_hi_to_si
1387 Target supports a vector widening summation of @code{short} operands
1388 into @code{int} results, or can promote (unpack) from @code{short}
1391 @item vect_widen_sum_qi_to_hi
1392 Target supports a vector widening summation of @code{char} operands
1393 into @code{short} results, or can promote (unpack) from @code{char}
1396 @item vect_widen_sum_qi_to_si
1397 Target supports a vector widening summation of @code{char} operands
1398 into @code{int} results.
1400 @item vect_widen_mult_qi_to_hi
1401 Target supports a vector widening multiplication of @code{char} operands
1402 into @code{short} results, or can promote (unpack) from @code{char} to
1403 @code{short} and perform non-widening multiplication of @code{short}.
1405 @item vect_widen_mult_hi_to_si
1406 Target supports a vector widening multiplication of @code{short} operands
1407 into @code{int} results, or can promote (unpack) from @code{short} to
1408 @code{int} and perform non-widening multiplication of @code{int}.
1411 Target supports a vector dot-product of @code{signed char}.
1414 Target supports a vector dot-product of @code{unsigned char}.
1417 Target supports a vector dot-product of @code{signed short}.
1420 Target supports a vector dot-product of @code{unsigned short}.
1422 @item vect_pack_trunc
1423 Target supports a vector demotion (packing) of @code{short} to @code{char}
1424 and from @code{int} to @code{short} using modulo arithmetic.
1427 Target supports a vector promotion (unpacking) of @code{char} to @code{short}
1428 and from @code{char} to @code{int}.
1430 @item vect_intfloat_cvt
1431 Target supports conversion from @code{signed int} to @code{float}.
1433 @item vect_uintfloat_cvt
1434 Target supports conversion from @code{unsigned int} to @code{float}.
1436 @item vect_floatint_cvt
1437 Target supports conversion from @code{float} to @code{signed int}.
1439 @item vect_floatuint_cvt
1440 Target supports conversion from @code{float} to @code{unsigned int}.
1443 @subsubsection Thread Local Storage attributes
1447 Target supports thread-local storage.
1450 Target supports native (rather than emulated) thread-local storage.
1453 Test system supports executing TLS executables.
1456 @subsubsection Decimal floating point attributes
1460 Targets supports compiling decimal floating point extension to C.
1463 Including the options used to compile this particular test, the
1464 target supports compiling decimal floating point extension to C.
1467 Test system can execute decimal floating point tests.
1470 Including the options used to compile this particular test, the
1471 test system can execute decimal floating point tests.
1474 Target generates decimal floating point instructions with current options.
1477 @subsubsection ARM-specific attributes
1481 ARM target generates 32-bit code.
1484 ARM target adheres to the ABI for the ARM Architecture.
1486 @item arm_hard_vfp_ok
1487 ARM target supports @code{-mfpu=vfp -mfloat-abi=hard}.
1488 Some multilibs may be incompatible with these options.
1491 ARM target supports @code{-mcpu=iwmmxt}.
1492 Some multilibs may be incompatible with this option.
1495 ARM target supports generating NEON instructions.
1498 Test system supports executing NEON instructions.
1501 @anchor{arm_neon_ok}
1502 ARM Target supports @code{-mfpu=neon -mfloat-abi=softfp} or compatible
1503 options. Some multilibs may be incompatible with these options.
1505 @item arm_neon_fp16_ok
1506 @anchor{arm_neon_fp16_ok}
1507 ARM Target supports @code{-mfpu=neon-fp16 -mfloat-abi=softfp} or compatible
1508 options. Some multilibs may be incompatible with these options.
1511 ARM target generates Thumb-1 code for @code{-mthumb}.
1514 ARM target generates Thumb-2 code for @code{-mthumb}.
1517 ARM target supports @code{-mfpu=vfp -mfloat-abi=softfp}.
1518 Some multilibs may be incompatible with these options.
1521 @subsubsection MIPS-specific attributes
1525 MIPS target supports 64-bit instructions.
1528 MIPS target does not produce MIPS16 code.
1530 @item mips16_attribute
1531 MIPS target can generate MIPS16 code.
1534 MIPS target is a Loongson-2E or -2F target using an ABI that supports
1535 the Loongson vector modes.
1537 @item mips_newabi_large_long_double
1538 MIPS target supports @code{long double} larger than @code{double}
1539 when using the new ABI.
1541 @item mpaired_single
1542 MIPS target supports @code{-mpaired-single}.
1545 @subsubsection PowerPC-specific attributes
1549 Test system supports executing 64-bit instructions.
1551 @item powerpc_altivec
1552 PowerPC target supports AltiVec.
1554 @item powerpc_altivec_ok
1555 PowerPC target supports @code{-maltivec}.
1558 PowerPC target supports floating-point registers.
1560 @item powerpc_hard_double
1561 PowerPC target supports hardware double-precision floating-point.
1563 @item powerpc_ppu_ok
1564 PowerPC target supports @code{-mcpu=cell}.
1567 PowerPC target supports PowerPC SPE.
1569 @item powerpc_spe_nocache
1570 Including the options used to compile this particular test, the
1571 PowerPC target supports PowerPC SPE.
1574 PowerPC target supports PowerPC SPU.
1576 @item spu_auto_overlay
1577 SPU target has toolchain that supports automatic overlay generation.
1579 @item powerpc_vsx_ok
1580 PowerPC target supports @code{-mvsx}.
1582 @item powerpc_405_nocache
1583 Including the options used to compile this particular test, the
1584 PowerPC target supports PowerPC 405.
1587 PowerPC target supports executing AltiVec instructions.
1590 @subsubsection Other hardware attributes
1594 Target supports compiling @code{avx} instructions.
1597 Target supports the execution of @code{avx} instructions.
1600 Test system can execute AltiVec and Cell PPU instructions.
1603 Target uses a ColdFire FPU.
1606 Target supports FPU instructions.
1609 Target supports compiling @code{sse} instructions.
1612 Target supports the execution of @code{sse} instructions.
1615 Target supports compiling @code{sse2} instructions.
1618 Target supports the execution of @code{sse2} instructions.
1620 @item sync_char_short
1621 Target supports atomic operations on @code{char} and @code{short}.
1624 Target supports atomic operations on @code{int} and @code{long}.
1627 Test environment appears to run executables on a simulator that
1628 accepts only @code{EM_SPARC} executables and chokes on @code{EM_SPARC32PLUS}
1629 or @code{EM_SPARCV9} executables.
1631 @item vect_cmdline_needed
1632 Target requires a command line argument to enable a SIMD instruction set.
1635 @subsubsection Environment attributes
1639 The language for the compiler under test is C.
1642 The language for the compiler under test is C++.
1645 Target provides a full C99 runtime.
1647 @item correct_iso_cpp_string_wchar_protos
1648 Target @code{string.h} and @code{wchar.h} headers provide C++ required
1649 overloads for @code{strchr} etc. functions.
1651 @item dummy_wcsftime
1652 Target uses a dummy @code{wcsftime} function that always returns zero.
1655 Target can truncate a file from a file descriptor, as used by
1656 @file{libgfortran/io/unix.c:fd_truncate}; i.e. @code{ftruncate} or
1660 Target is @samp{freestanding} as defined in section 4 of the C99 standard.
1661 Effectively, it is a target which supports no extra headers or libraries
1662 other than what is considered essential.
1665 Target supports constructors with initialization priority arguments.
1667 @item inttypes_types
1668 Target has the basic signed and unsigned types in @code{inttypes.h}.
1669 This is for tests that GCC's notions of these types agree with those
1670 in the header, as some systems have only @code{inttypes.h}.
1673 Target might have errors of a few ULP in string to floating-point
1674 conversion functions and overflow is not always detected correctly by
1678 Target supports Newlib.
1681 Target provides @code{pow10} function.
1684 Target can compile using @code{pthread.h} with no errors or warnings.
1687 Target has @code{pthread.h}.
1689 @item run_expensive_tests
1690 Expensive testcases (usually those that consume excessive amounts of CPU
1691 time) should be run on this target. This can be enabled by setting the
1692 @env{GCC_TEST_RUN_EXPENSIVE} environment variable to a non-empty string.
1695 Test system runs executables on a simulator (i.e. slowly) rather than
1696 hardware (i.e. fast).
1699 Target has the basic signed and unsigned C types in @code{stdint.h}.
1700 This will be obsolete when GCC ensures a working @code{stdint.h} for
1704 Target supports trampolines.
1707 Target supports uClibc.
1710 Target does not use a status wrapper.
1712 @item vxworks_kernel
1713 Target is a VxWorks kernel.
1716 Target is a VxWorks RTP.
1719 Target supports wide characters.
1722 @subsubsection Other attributes
1725 @item automatic_stack_alignment
1726 Target supports automatic stack alignment.
1729 Target uses @code{__cxa_atexit}.
1731 @item default_packed
1732 Target has packed layout of structure members by default.
1735 Target supports Graphite optimizations.
1738 Target supports fixed-point extension to C.
1741 Target supports OpenMP via @option{-fopenmp}.
1744 Target supports @option{-fpic} and @option{-fPIC}.
1747 Target supports @option{-freorder-blocks-and-partition}.
1749 @item fstack_protector
1750 Target supports @option{-fstack-protector}.
1753 Target uses GNU @command{as}.
1756 Target supports @option{--gc-sections}.
1758 @item keeps_null_pointer_checks
1759 Target keeps null pointer checks, either due to the use of
1760 @option{-fno-delete-null-pointer-checks} or hardwired into the target.
1763 Compiler has been configured to support link-time optimization (LTO).
1765 @item named_sections
1766 Target supports named sections.
1768 @item natural_alignment_32
1769 Target uses natural alignment (aligned to type size) for types of
1772 @item target_natural_alignment_64
1773 Target uses natural alignment (aligned to type size) for types of
1777 Target does not generate PIC by default.
1779 @item pcc_bitfield_type_matters
1780 Target defines @code{PCC_BITFIELD_TYPE_MATTERS}.
1782 @item pe_aligned_commons
1783 Target supports @option{-mpe-aligned-commons}.
1785 @item section_anchors
1786 Target supports section anchors.
1789 Target defaults to short enums.
1792 Target supports @option{-static}.
1794 @item static_libgfortran
1795 Target supports statically linking @samp{libgfortran}.
1797 @item string_merging
1798 Target supports merging string constants at link time.
1801 Target supports compiling and assembling UCN.
1804 Including the options used to compile this particular test, the
1805 target supports compiling and assembling UCN.
1807 @item unaligned_stack
1808 Target does not guarantee that its @code{STACK_BOUNDARY} is greater than
1809 or equal to the required vector alignment.
1811 @item vector_alignment_reachable
1812 Vector alignment is reachable for types of 32 bits or less.
1814 @item vector_alignment_reachable_for_64bit
1815 Vector alignment is reachable for types of 64 bits or less.
1817 @item wchar_t_char16_t_compatible
1818 Target supports @code{wchar_t} that is compatible with @code{char16_t}.
1820 @item wchar_t_char32_t_compatible
1821 Target supports @code{wchar_t} that is compatible with @code{char32_t}.
1824 @subsubsection Local to tests in @code{gcc.target/i386}
1828 Target supports compiling @code{3dnow} instructions.
1831 Target supports compiling @code{aes} instructions.
1834 Target supports compiling @code{fma4} instructions.
1836 @item ms_hook_prologue
1837 Target supports attribute @code{ms_hook_prologue}.
1840 Target supports compiling @code{pclmul} instructions.
1843 Target supports compiling @code{sse3} instructions.
1846 Target supports compiling @code{sse4} instructions.
1849 Target supports compiling @code{sse4a} instructions.
1852 Target supports compiling @code{ssse3} instructions.
1855 Target supports compiling @code{vaes} instructions.
1858 Target supports compiling @code{vpclmul} instructions.
1861 Target supports compiling @code{xop} instructions.
1864 @subsubsection Local to tests in @code{gcc.target/spu/ea}
1868 Target @code{__ea} library functions are available.
1871 @subsubsection Local to tests in @code{gcc.test-framework}
1882 @subsection Features for @code{dg-add-options}
1884 The supported values of @var{feature} for directive @code{dg-add-options}
1889 NEON support. Only ARM targets support this feature, and only then
1890 in certain modes; see the @ref{arm_neon_ok,,arm_neon_ok effective target
1894 NEON and half-precision floating point support. Only ARM targets
1895 support this feature, and only then in certain modes; see
1896 the @ref{arm_neon_ok,,arm_neon_fp16_ok effective target keyword}.
1898 @item bind_pic_locally
1899 Add the target-specific flags needed to enable functions to bind
1900 locally when using pic/PIC passes in the testsuite.
1903 Add the target-specific flags needed to access the C99 runtime.
1906 Add the target-specific flags needed to enable full IEEE
1909 @item mips16_attribute
1910 @code{mips16} function attributes.
1911 Only MIPS targets support this feature, and only then in certain modes.
1914 Add the target-specific flags needed to use thread-local storage.
1917 @node Require Support
1918 @subsection Variants of @code{dg-require-@var{support}}
1920 A few of the @code{dg-require} directives take arguments.
1923 @item dg-require-iconv @var{codeset}
1924 Skip the test if the target does not support iconv. @var{codeset} is
1925 the codeset to convert to.
1927 @item dg-require-profiling @var{profopt}
1928 Skip the test if the target does not support profiling with option
1931 @item dg-require-visibility @var{vis}
1932 Skip the test if the target does not support the @code{visibility} attribute.
1933 If @var{vis} is @code{""}, support for @code{visibility("hidden")} is
1934 checked, for @code{visibility("@var{vis}")} otherwise.
1937 The original @code{dg-require} directives were defined before there
1938 was support for effective-target keywords. The directives that do not
1939 take arguments could be replaced with effective-target keywords.
1942 @item dg-require-alias ""
1943 Skip the test if the target does not support the @samp{alias} attribute.
1945 @item dg-require-ascii-locale ""
1946 Skip the test if the host does not support an ASCII locale.
1948 @item dg-require-compat-dfp ""
1949 Skip this test unless both compilers in a @file{compat} testsuite
1950 support decimal floating point.
1952 @item dg-require-cxa-atexit ""
1953 Skip the test if the target does not support @code{__cxa_atexit}.
1954 This is equivalent to @code{dg-require-effective-target cxa_atexit}.
1956 @item dg-require-dll ""
1957 Skip the test if the target does not support DLL attributes.
1959 @item dg-require-fork ""
1960 Skip the test if the target does not support @code{fork}.
1962 @item dg-require-gc-sections ""
1963 Skip the test if the target's linker does not support the
1964 @code{--gc-sections} flags.
1965 This is equivalent to @code{dg-require-effective-target gc-sections}.
1967 @item dg-require-host-local ""
1968 Skip the test if the host is remote, rather than the same as the build
1969 system. Some tests are incompatible with DejaGnu's handling of remote
1970 hosts, which involves copying the source file to the host and compiling
1971 it with a relative path and "@code{-o a.out}".
1973 @item dg-require-mkfifo ""
1974 Skip the test if the target does not support @code{mkfifo}.
1976 @item dg-require-named-sections ""
1977 Skip the test is the target does not support named sections.
1978 This is equivalent to @code{dg-require-effective-target named_sections}.
1980 @item dg-require-weak ""
1981 Skip the test if the target does not support weak symbols.
1983 @item dg-require-weak-override ""
1984 Skip the test if the target does not support overriding weak symbols.
1988 @subsection Commands for use in @code{dg-final}
1990 The GCC testsuite defines the following directives to be used within
1993 @subsubsection Scan a particular file
1996 @item scan-file @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
1997 Passes if @var{regexp} matches text in @var{filename}.
1998 @item scan-file-not @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
1999 Passes if @var{regexp} does not match text in @var{filename}.
2000 @item scan-module @var{module} @var{regexp} [@{ target/xfail @var{selector} @}]
2001 Passes if @var{regexp} matches in Fortran module @var{module}.
2004 @subsubsection Scan the assembly output
2007 @item scan-assembler @var{regex} [@{ target/xfail @var{selector} @}]
2008 Passes if @var{regex} matches text in the test's assembler output.
2010 @item scan-assembler-not @var{regex} [@{ target/xfail @var{selector} @}]
2011 Passes if @var{regex} does not match text in the test's assembler output.
2013 @item scan-assembler-times @var{regex} @var{num} [@{ target/xfail @var{selector} @}]
2014 Passes if @var{regex} is matched exactly @var{num} times in the test's
2017 @item scan-assembler-dem @var{regex} [@{ target/xfail @var{selector} @}]
2018 Passes if @var{regex} matches text in the test's demangled assembler output.
2020 @item scan-assembler-dem-not @var{regex} [@{ target/xfail @var{selector} @}]
2021 Passes if @var{regex} does not match text in the test's demangled assembler
2024 @item scan-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2025 Passes if @var{symbol} is defined as a hidden symbol in the test's
2028 @item scan-not-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2029 Passes if @var{symbol} is not defined as a hidden symbol in the test's
2033 @subsubsection Scan optimization dump files
2035 These commands are available for @var{kind} of @code{tree}, @code{rtl},
2039 @item scan-@var{kind}-dump @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2040 Passes if @var{regex} matches text in the dump file with suffix @var{suffix}.
2042 @item scan-@var{kind}-dump-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2043 Passes if @var{regex} does not match text in the dump file with suffix
2046 @item scan-@var{kind}-dump-times @var{regex} @var{num} @var{suffix} [@{ target/xfail @var{selector} @}]
2047 Passes if @var{regex} is found exactly @var{num} times in the dump file
2048 with suffix @var{suffix}.
2050 @item scan-@var{kind}-dump-dem @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2051 Passes if @var{regex} matches demangled text in the dump file with
2052 suffix @var{suffix}.
2054 @item scan-@var{kind}-dump-dem-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2055 Passes if @var{regex} does not match demangled text in the dump file with
2056 suffix @var{suffix}.
2059 @subsubsection Verify that an output files exists or not
2062 @item output-exists [@{ target/xfail @var{selector} @}]
2063 Passes if compiler output file exists.
2065 @item output-exists-not [@{ target/xfail @var{selector} @}]
2066 Passes if compiler output file does not exist.
2069 @subsubsection Check for LTO tests
2072 @item scan-symbol @var{regexp} [@{ target/xfail @var{selector} @}]
2073 Passes if the pattern is present in the final executable.
2076 @subsubsection Checks for @command{gcov} tests
2079 @item run-gcov @var{sourcefile}
2080 Check line counts in @command{gcov} tests.
2082 @item run-gcov [branches] [calls] @{ @var{opts} @var{sourcefile} @}
2083 Check branch and/or call counts, in addition to line counts, in
2084 @command{gcov} tests.
2087 @subsubsection Clean up generated test files
2090 @item cleanup-coverage-files
2091 Removes coverage data files generated for this test.
2093 @item cleanup-ipa-dump @var{suffix}
2094 Removes IPA dump files generated for this test.
2096 @item cleanup-modules
2097 Removes Fortran module files generated for this test.
2099 @item cleanup-profile-file
2100 Removes profiling files generated for this test.
2102 @item cleanup-repo-files
2103 Removes files generated for this test for @option{-frepo}.
2105 @item cleanup-rtl-dump @var{suffix}
2106 Removes RTL dump files generated for this test.
2108 @item cleanup-saved-temps
2109 Removes files for the current test which were kept for @option{-save-temps}.
2111 @item cleanup-tree-dump @var{suffix}
2112 Removes tree dump files matching @var{suffix} which were generated for
2117 @section Ada Language Testsuites
2119 The Ada testsuite includes executable tests from the ACATS
2120 testsuite, publicly available at
2121 @uref{http://www.ada-auth.org/acats.html}.
2123 These tests are integrated in the GCC testsuite in the
2124 @file{ada/acats} directory, and
2125 enabled automatically when running @code{make check}, assuming
2126 the Ada language has been enabled when configuring GCC@.
2128 You can also run the Ada testsuite independently, using
2129 @code{make check-ada}, or run a subset of the tests by specifying which
2130 chapter to run, e.g.:
2133 $ make check-ada CHAPTERS="c3 c9"
2136 The tests are organized by directory, each directory corresponding to
2137 a chapter of the Ada Reference Manual. So for example, @file{c9} corresponds
2138 to chapter 9, which deals with tasking features of the language.
2140 There is also an extra chapter called @file{gcc} containing a template for
2141 creating new executable tests, although this is deprecated in favor of
2142 the @file{gnat.dg} testsuite.
2144 The tests are run using two @command{sh} scripts: @file{run_acats} and
2145 @file{run_all.sh}. To run the tests using a simulator or a cross
2146 target, see the small
2147 customization section at the top of @file{run_all.sh}.
2149 These tests are run using the build tree: they can be run without doing
2150 a @code{make install}.
2153 @section C Language Testsuites
2155 GCC contains the following C language testsuites, in the
2156 @file{gcc/testsuite} directory:
2160 This contains tests of particular features of the C compiler, using the
2161 more modern @samp{dg} harness. Correctness tests for various compiler
2162 features should go here if possible.
2164 Magic comments determine whether the file
2165 is preprocessed, compiled, linked or run. In these tests, error and warning
2166 message texts are compared against expected texts or regular expressions
2167 given in comments. These tests are run with the options @samp{-ansi -pedantic}
2168 unless other options are given in the test. Except as noted below they
2169 are not run with multiple optimization options.
2171 This subdirectory contains tests for binary compatibility using
2172 @file{lib/compat.exp}, which in turn uses the language-independent support
2173 (@pxref{compat Testing, , Support for testing binary compatibility}).
2175 This subdirectory contains tests of the preprocessor.
2177 This subdirectory contains tests for debug formats. Tests in this
2178 subdirectory are run for each debug format that the compiler supports.
2180 This subdirectory contains tests of the @option{-Wformat} format
2181 checking. Tests in this directory are run with and without
2183 @item gcc.dg/noncompile
2184 This subdirectory contains tests of code that should not compile and
2185 does not need any special compilation options. They are run with
2186 multiple optimization options, since sometimes invalid code crashes
2187 the compiler with optimization.
2188 @item gcc.dg/special
2189 FIXME: describe this.
2192 This contains particular code fragments which have historically broken easily.
2193 These tests are run with multiple optimization options, so tests for features
2194 which only break at some optimization levels belong here. This also contains
2195 tests to check that certain optimizations occur. It might be worthwhile to
2196 separate the correctness tests cleanly from the code quality tests, but
2197 it hasn't been done yet.
2199 @item gcc.c-torture/compat
2200 FIXME: describe this.
2202 This directory should probably not be used for new tests.
2203 @item gcc.c-torture/compile
2204 This testsuite contains test cases that should compile, but do not
2205 need to link or run. These test cases are compiled with several
2206 different combinations of optimization options. All warnings are
2207 disabled for these test cases, so this directory is not suitable if
2208 you wish to test for the presence or absence of compiler warnings.
2209 While special options can be set, and tests disabled on specific
2210 platforms, by the use of @file{.x} files, mostly these test cases
2211 should not contain platform dependencies. FIXME: discuss how defines
2212 such as @code{NO_LABEL_VALUES} and @code{STACK_SIZE} are used.
2213 @item gcc.c-torture/execute
2214 This testsuite contains test cases that should compile, link and run;
2215 otherwise the same comments as for @file{gcc.c-torture/compile} apply.
2216 @item gcc.c-torture/execute/ieee
2217 This contains tests which are specific to IEEE floating point.
2218 @item gcc.c-torture/unsorted
2219 FIXME: describe this.
2221 This directory should probably not be used for new tests.
2222 @item gcc.misc-tests
2223 This directory contains C tests that require special handling. Some
2224 of these tests have individual expect files, and others share
2225 special-purpose expect files:
2228 @item @code{bprob*.c}
2229 Test @option{-fbranch-probabilities} using
2230 @file{gcc.misc-tests/bprob.exp}, which
2231 in turn uses the generic, language-independent framework
2232 (@pxref{profopt Testing, , Support for testing profile-directed
2235 @item @code{gcov*.c}
2236 Test @command{gcov} output using @file{gcov.exp}, which in turn uses the
2237 language-independent support (@pxref{gcov Testing, , Support for testing gcov}).
2239 @item @code{i386-pf-*.c}
2240 Test i386-specific support for data prefetch using @file{i386-prefetch.exp}.
2243 @item gcc.test-framework
2246 Test the testsuite itself using @file{gcc.test-framework/test-framework.exp}.
2251 FIXME: merge in @file{testsuite/README.gcc} and discuss the format of
2252 test cases and magic comments more.
2255 @section The Java library testsuites.
2257 Runtime tests are executed via @samp{make check} in the
2258 @file{@var{target}/libjava/testsuite} directory in the build
2259 tree. Additional runtime tests can be checked into this testsuite.
2261 Regression testing of the core packages in libgcj is also covered by the
2262 Mauve testsuite. The @uref{http://sourceware.org/mauve/,,Mauve Project}
2263 develops tests for the Java Class Libraries. These tests are run as part
2264 of libgcj testing by placing the Mauve tree within the libjava testsuite
2265 sources at @file{libjava/testsuite/libjava.mauve/mauve}, or by specifying
2266 the location of that tree when invoking @samp{make}, as in
2267 @samp{make MAUVEDIR=~/mauve check}.
2269 To detect regressions, a mechanism in @file{mauve.exp} compares the
2270 failures for a test run against the list of expected failures in
2271 @file{libjava/testsuite/libjava.mauve/xfails} from the source hierarchy.
2272 Update this file when adding new failing tests to Mauve, or when fixing
2273 bugs in libgcj that had caused Mauve test failures.
2275 We encourage developers to contribute test cases to Mauve.
2278 @section Support for testing link-time optimizations
2280 Tests for link-time optimizations usually require multiple source files
2281 that are compiled separately, perhaps with different sets of options.
2282 There are several special-purpose test directives used for these tests.
2285 @item @{ dg-lto-do @var{do-what-keyword} @}
2286 @var{do-what-keyword} specifies how the test is compiled and whether
2287 it is executed. It is one of:
2291 Compile with @option{-c} to produce a relocatable object file.
2293 Compile, assemble, and link to produce an executable file.
2295 Produce and run an executable file, which is expected to return
2299 The default is @code{assemble}. That can be overridden for a set of
2300 tests by redefining @code{dg-do-what-default} within the @code{.exp}
2301 file for those tests.
2303 Unlike @code{dg-do}, @code{dg-lto-do} does not support an optional
2304 @samp{target} or @samp{xfail} list. Use @code{dg-skip-if},
2305 @code{dg-xfail-if}, or @code{dg-xfail-run-if}.
2307 @item @{ dg-lto-options @{ @{ @var{options} @} [@{ @var{options} @}] @} [@{ target @var{selector} @}]@}
2308 This directive provides a list of one or more sets of compiler options
2309 to override @var{LTO_OPTIONS}. Each test will be compiled and run with
2310 each of these sets of options.
2312 @item @{ dg-extra-ld-options @var{options} [@{ target @var{selector} @}]@}
2313 This directive adds @var{options} to the linker options used.
2315 @item @{ dg-suppress-ld-options @var{options} [@{ target @var{selector} @}]@}
2316 This directive removes @var{options} from the set of linker options used.
2320 @section Support for testing @command{gcov}
2322 Language-independent support for testing @command{gcov}, and for checking
2323 that branch profiling produces expected values, is provided by the
2324 expect file @file{lib/gcov.exp}. @command{gcov} tests also rely on procedures
2325 in @file{lib/gcc-dg.exp} to compile and run the test program. A typical
2326 @command{gcov} test contains the following DejaGnu commands within comments:
2329 @{ dg-options "-fprofile-arcs -ftest-coverage" @}
2330 @{ dg-do run @{ target native @} @}
2331 @{ dg-final @{ run-gcov sourcefile @} @}
2334 Checks of @command{gcov} output can include line counts, branch percentages,
2335 and call return percentages. All of these checks are requested via
2336 commands that appear in comments in the test's source file.
2337 Commands to check line counts are processed by default.
2338 Commands to check branch percentages and call return percentages are
2339 processed if the @command{run-gcov} command has arguments @code{branches}
2340 or @code{calls}, respectively. For example, the following specifies
2341 checking both, as well as passing @option{-b} to @command{gcov}:
2344 @{ dg-final @{ run-gcov branches calls @{ -b sourcefile @} @} @}
2347 A line count command appears within a comment on the source line
2348 that is expected to get the specified count and has the form
2349 @code{count(@var{cnt})}. A test should only check line counts for
2350 lines that will get the same count for any architecture.
2352 Commands to check branch percentages (@code{branch}) and call
2353 return percentages (@code{returns}) are very similar to each other.
2354 A beginning command appears on or before the first of a range of
2355 lines that will report the percentage, and the ending command
2356 follows that range of lines. The beginning command can include a
2357 list of percentages, all of which are expected to be found within
2358 the range. A range is terminated by the next command of the same
2359 kind. A command @code{branch(end)} or @code{returns(end)} marks
2360 the end of a range without starting a new one. For example:
2363 if (i > 10 && j > i && j < 20) /* @r{branch(27 50 75)} */
2364 /* @r{branch(end)} */
2368 For a call return percentage, the value specified is the
2369 percentage of calls reported to return. For a branch percentage,
2370 the value is either the expected percentage or 100 minus that
2371 value, since the direction of a branch can differ depending on the
2372 target or the optimization level.
2374 Not all branches and calls need to be checked. A test should not
2375 check for branches that might be optimized away or replaced with
2376 predicated instructions. Don't check for calls inserted by the
2377 compiler or ones that might be inlined or optimized away.
2379 A single test can check for combinations of line counts, branch
2380 percentages, and call return percentages. The command to check a
2381 line count must appear on the line that will report that count, but
2382 commands to check branch percentages and call return percentages can
2383 bracket the lines that report them.
2385 @node profopt Testing
2386 @section Support for testing profile-directed optimizations
2388 The file @file{profopt.exp} provides language-independent support for
2389 checking correct execution of a test built with profile-directed
2390 optimization. This testing requires that a test program be built and
2391 executed twice. The first time it is compiled to generate profile
2392 data, and the second time it is compiled to use the data that was
2393 generated during the first execution. The second execution is to
2394 verify that the test produces the expected results.
2396 To check that the optimization actually generated better code, a
2397 test can be built and run a third time with normal optimizations to
2398 verify that the performance is better with the profile-directed
2399 optimizations. @file{profopt.exp} has the beginnings of this kind
2402 @file{profopt.exp} provides generic support for profile-directed
2403 optimizations. Each set of tests that uses it provides information
2404 about a specific optimization:
2408 tool being tested, e.g., @command{gcc}
2410 @item profile_option
2411 options used to generate profile data
2413 @item feedback_option
2414 options used to optimize using that profile data
2417 suffix of profile data files
2419 @item PROFOPT_OPTIONS
2420 list of options with which to run each test, similar to the lists for
2423 @item @{ dg-final-generate @{ @var{local-directive} @} @}
2424 This directive is similar to @code{dg-final}, but the
2425 @var{local-directive} is run after the generation of profile data.
2427 @item @{ dg-final-use @{ @var{local-directive} @} @}
2428 The @var{local-directive} is run after the profile data have been
2432 @node compat Testing
2433 @section Support for testing binary compatibility
2435 The file @file{compat.exp} provides language-independent support for
2436 binary compatibility testing. It supports testing interoperability of
2437 two compilers that follow the same ABI, or of multiple sets of
2438 compiler options that should not affect binary compatibility. It is
2439 intended to be used for testsuites that complement ABI testsuites.
2441 A test supported by this framework has three parts, each in a
2442 separate source file: a main program and two pieces that interact
2443 with each other to split up the functionality being tested.
2446 @item @var{testname}_main.@var{suffix}
2447 Contains the main program, which calls a function in file
2448 @file{@var{testname}_x.@var{suffix}}.
2450 @item @var{testname}_x.@var{suffix}
2451 Contains at least one call to a function in
2452 @file{@var{testname}_y.@var{suffix}}.
2454 @item @var{testname}_y.@var{suffix}
2455 Shares data with, or gets arguments from,
2456 @file{@var{testname}_x.@var{suffix}}.
2459 Within each test, the main program and one functional piece are
2460 compiled by the GCC under test. The other piece can be compiled by
2461 an alternate compiler. If no alternate compiler is specified,
2462 then all three source files are all compiled by the GCC under test.
2463 You can specify pairs of sets of compiler options. The first element
2464 of such a pair specifies options used with the GCC under test, and the
2465 second element of the pair specifies options used with the alternate
2466 compiler. Each test is compiled with each pair of options.
2468 @file{compat.exp} defines default pairs of compiler options.
2469 These can be overridden by defining the environment variable
2470 @env{COMPAT_OPTIONS} as:
2473 COMPAT_OPTIONS="[list [list @{@var{tst1}@} @{@var{alt1}@}]
2474 @dots{}[list @{@var{tstn}@} @{@var{altn}@}]]"
2477 where @var{tsti} and @var{alti} are lists of options, with @var{tsti}
2478 used by the compiler under test and @var{alti} used by the alternate
2479 compiler. For example, with
2480 @code{[list [list @{-g -O0@} @{-O3@}] [list @{-fpic@} @{-fPIC -O2@}]]},
2481 the test is first built with @option{-g -O0} by the compiler under
2482 test and with @option{-O3} by the alternate compiler. The test is
2483 built a second time using @option{-fpic} by the compiler under test
2484 and @option{-fPIC -O2} by the alternate compiler.
2486 An alternate compiler is specified by defining an environment
2487 variable to be the full pathname of an installed compiler; for C
2488 define @env{ALT_CC_UNDER_TEST}, and for C++ define
2489 @env{ALT_CXX_UNDER_TEST}. These will be written to the
2490 @file{site.exp} file used by DejaGnu. The default is to build each
2491 test with the compiler under test using the first of each pair of
2492 compiler options from @env{COMPAT_OPTIONS}. When
2493 @env{ALT_CC_UNDER_TEST} or
2494 @env{ALT_CXX_UNDER_TEST} is @code{same}, each test is built using
2495 the compiler under test but with combinations of the options from
2496 @env{COMPAT_OPTIONS}.
2498 To run only the C++ compatibility suite using the compiler under test
2499 and another version of GCC using specific compiler options, do the
2500 following from @file{@var{objdir}/gcc}:
2505 ALT_CXX_UNDER_TEST=$@{alt_prefix@}/bin/g++ \
2506 COMPAT_OPTIONS="@var{lists as shown above}" \
2508 RUNTESTFLAGS="compat.exp"
2511 A test that fails when the source files are compiled with different
2512 compilers, but passes when the files are compiled with the same
2513 compiler, demonstrates incompatibility of the generated code or
2514 runtime support. A test that fails for the alternate compiler but
2515 passes for the compiler under test probably tests for a bug that was
2516 fixed in the compiler under test but is present in the alternate
2519 The binary compatibility tests support a small number of test framework
2520 commands that appear within comments in a test file.
2524 These commands can be used in @file{@var{testname}_main.@var{suffix}}
2525 to skip the test if specific support is not available on the target.
2528 The specified options are used for compiling this particular source
2529 file, appended to the options from @env{COMPAT_OPTIONS}. When this
2530 command appears in @file{@var{testname}_main.@var{suffix}} the options
2531 are also used to link the test program.
2534 This command can be used in a secondary source file to specify that
2535 compilation is expected to fail for particular options on particular
2540 @section Support for torture testing using multiple options
2542 Throughout the compiler testsuite there are several directories whose
2543 tests are run multiple times, each with a different set of options.
2544 These are known as torture tests.
2545 @file{lib/torture-options.exp} defines procedures to
2550 Initialize use of torture lists.
2551 @item set-torture-options
2552 Set lists of torture options to use for tests with and without loops.
2553 Optionally combine a set of torture options with a set of other
2554 options, as is done with Objective-C runtime options.
2555 @item torture-finish
2556 Finalize use of torture lists.
2559 The @file{.exp} file for a set of tests that use torture options must
2560 include calls to these three procedures if:
2563 @item It calls @code{gcc-dg-runtest} and overrides @var{DG_TORTURE_OPTIONS}.
2565 @item It calls @var{$@{tool@}}@code{-torture} or
2566 @var{$@{tool@}}@code{-torture-execute}, where @var{tool} is @code{c},
2567 @code{fortran}, or @code{objc}.
2569 @item It calls @code{dg-pch}.
2572 It is not necessary for a @file{.exp} file that calls @code{gcc-dg-runtest}
2573 to call the torture procedures if the tests should use the list in
2574 @var{DG_TORTURE_OPTIONS} defined in @file{gcc-dg.exp}.
2576 Most uses of torture options can override the default lists by defining
2577 @var{TORTURE_OPTIONS} or add to the default list by defining
2578 @var{ADDITIONAL_TORTURE_OPTIONS}. Define these in a @file{.dejagnurc}
2579 file or add them to the @file{site.exp} file; for example
2582 set ADDITIONAL_TORTURE_OPTIONS [list \
2583 @{ -O2 -ftree-loop-linear @} \
2584 @{ -O2 -fpeel-loops @} ]